ISO and North American paper sizes in millimetres, inches and points, plus a custom-unit converter.
Standard sizes
Custom (mm or in)
1 inch = 25.4 mm exactly.
Solve the internal rate of return for any cash-flow table with Newton-Raphson and a bisection fallback.
Monthly payment plus a full amortisation table with principal, interest, extra payments and the running balance.
Turn system size, peak sun hours and installed cost into annual kWh and a lifetime saving against a rising grid price.
Exact conversion factors across length, mass, area, volume, speed, temperature and data, with the whole category converted at once.
Read text aloud with the voices on your device.
Record, trim and download clips locally.
Record or upload audio and change your voice with 12 DSP presets, then save a WAV.
Generate tones and effects with the Web Audio API.
